Survival of the Fitter

In this final chapter, Lieberman summarizes his conclusions, and lists potential solutions to the problem of mismatch diseases.  The first solution is to let natural selection sort everything out.  Although this is a heartless solution, Lieberman admits that natural selection continues to act on the human population.  However, natural selection is unlike to act on mismatch diseases that occur later in life, because they often have no effect on reproduction.  The second solution is to invest more in biomedical research and treatment.  Lieberman supports increasing biomedical research, but warns that there likely will be no large breakthrough, but only small incremental progress.  Additionally, drug treatments usually do not cure chronic diseases, and can cause unpleasant side effects.  It is also difficult to target the cause of chronic diseases, and instead symptoms are treated.  Lieberman maintains that one of the best ways to prevent mismatch diseases are to eat healthy and exercise.  This leads to the third solution, which is to educate and empower.  People should learn how their bodies work, and how to prevent chronic mismatch diseases.  Lieberman points out that advertisers commonly market tasty and unhealthy food, but there are very few messages about proper nutrition and exercise.  The fourth solution is to change the environment.  The logic is that sometimes humans need external forces to force change.  Examples of this are to require physical exercise in schools or ban fast food from school cafeterias.  When in comes to adults, the government cannot ban unhealthy food, but it discourage consumption of soda and fast food with taxes.  The government could also require warnings similar to ones on cigarettes currently.  As a final message, Lieberman reminds us that “Nothing in biology makes sense except in the light of evolution”.  He reminds us that human evolution was not a triumph of brains over brawn, and that we cannot fix problems with our biology.  Instead of waiting for scientists to cure diabetes or heart disease, we should pay attention to our body, and attempt to prevent chronic illnesses with nutrition and exercise.